# Iron Block Vs. Aluminum block **URL:** \ **Category:** SON240sx Automotive\ **Created:** [December 12, 2004, 6:03pm UTC](https://forums.speedlife.net/t/iron-block-vs-aluminum-block/82454 "2004-12-12T18:03:48Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![GT1](https://avatars.discourse-cdn.com/v4/letter/g/b5e925/32.png) [@GT1](https://forums.speedlife.net/u/GT1)\ **Post date:** [December 19, 2004, 8:29pm UTC](https://forums.speedlife.net/t/iron-block-vs-aluminum-block/82454/21 "2004-12-19T20:29:35Z")
> [@SHIFT\_SR20DET](#): > > [quote=Hector]iron block is stronger, but i would choose aluminium for one reason, we have aluminium heads!!! > > aluminium and iron have different expansion rates, using dissimilar metals is never a good idea, with iron blocks and aluminium heads u tend to get head warpage more than u would iif both were aluminium, > > also aluminium dissapates heat quicker than iron, exactly what u want in a high performance motor, less chance of heat soak into the engine bay after engine shut off as well, cuz as we all know heat soak creates a whole whack of problems! > > Engines with dissimilar metals for head and block tend to have more headgasket problems as well!! > > just my two cents And you got this information from where?[/quote] that post does make sence really… GT ---
**Author:** ![Ed1](https://avatars.discourse-cdn.com/v4/letter/e/958977/32.png) [@Ed1](https://forums.speedlife.net/u/Ed1)\ **Post date:** [December 20, 2004, 1:25pm UTC](https://forums.speedlife.net/t/iron-block-vs-aluminum-block/82454/22 "2004-12-20T13:25:29Z")
> that post does make sence really… > > GT yeah it does, but I can’t find any info to support it. however, I do know that alluminum expands 2 times faster than steel. steel made from iron?! I dunno lol not pro at physics/chem, more into biology ---
**Author:** ![Polak182](https://avatars.discourse-cdn.com/v4/letter/p/7feea3/32.png) [@Polak182](https://forums.speedlife.net/u/Polak182)\ **Post date:** [December 20, 2004, 1:48pm UTC](https://forums.speedlife.net/t/iron-block-vs-aluminum-block/82454/23 "2004-12-20T13:48:12Z")
> [@spilner](#): > > theres a reason the SR is so popular… > > dont second guess the pro’s. > > ARUMINURMN BROCKK!!! DORIIIFFFTTTTOOOOUUUUUU!!! Sr’s are popular because the head cover looks nicer than the CA n’ KA and becuase it has 30hp more than the CA and 45hp more than a KA. Also has a turbo, which KA’s don’t. It has nothing to do with the metal used to make it. You think that people care? I think they go with what everyone else has. ps. KA’s have Iron or aluminum? ---
**Author:** ![SHIFT\_KA24DET](https://avatars.discourse-cdn.com/v4/letter/s/b9bd4f/32.png) [@SHIFT\_KA24DET](https://forums.speedlife.net/u/SHIFT_KA24DET)\ **Post date:** [December 20, 2004, 1:50pm UTC](https://forums.speedlife.net/t/iron-block-vs-aluminum-block/82454/24 "2004-12-20T13:50:05Z")
> [@Polak182](#): > > ps. KA’s have Iron or aluminum? They have Aluminum Heads and Iron Blocks. ---
**Author:** ![SHIFT\_KA24DET](https://avatars.discourse-cdn.com/v4/letter/s/b9bd4f/32.png) [@SHIFT\_KA24DET](https://forums.speedlife.net/u/SHIFT_KA24DET)\ **Post date:** [December 20, 2004, 1:50pm UTC](https://forums.speedlife.net/t/iron-block-vs-aluminum-block/82454/25 "2004-12-20T13:50:46Z")
> [@GT\_GREG](#): > > [quote=SHIFT\_SR20DET][quote=Hector]iron block is stronger, but i would choose aluminium for one reason, we have aluminium heads!!! > > aluminium and iron have different expansion rates, using dissimilar metals is never a good idea, with iron blocks and aluminium heads u tend to get head warpage more than u would iif both were aluminium, > > also aluminium dissapates heat quicker than iron, exactly what u want in a high performance motor, less chance of heat soak into the engine bay after engine shut off as well, cuz as we all know heat soak creates a whole whack of problems! > > Engines with dissimilar metals for head and block tend to have more headgasket problems as well!! > > just my two cents And you got this information from where?[/quote] that post does make sence really… GT[/quote] It does and it doesn’t. What I was asking for was some Supporting Evidence or Factual Data that backs it up. ---
**Author:** ![Polak182](https://avatars.discourse-cdn.com/v4/letter/p/7feea3/32.png) [@Polak182](https://forums.speedlife.net/u/Polak182)\ **Post date:** [December 20, 2004, 1:51pm UTC](https://forums.speedlife.net/t/iron-block-vs-aluminum-block/82454/26 "2004-12-20T13:51:00Z")
and what kind of head do the Sr’s have? iron? I know the block is aluminum ---
**Author:** ![SHIFT\_KA24DET](https://avatars.discourse-cdn.com/v4/letter/s/b9bd4f/32.png) [@SHIFT\_KA24DET](https://forums.speedlife.net/u/SHIFT_KA24DET)\ **Post date:** [December 20, 2004, 1:56pm UTC](https://forums.speedlife.net/t/iron-block-vs-aluminum-block/82454/27 "2004-12-20T13:56:38Z")
They have both Aluminum head and block, but poor valvtrain design… [Previous page](https://forums.speedlife.net/t/iron-block-vs-aluminum-block/82454.md?page=1)